Try also to play around with the shadow dials on the lights. They are set to 100% by default, but since Poser lacks ray tracing (until Poser 5...) and other fancy rendering features, all shadows will get very dark. Real life shadows are very seldom totally dark, there will always be light reflected from surrounding areas. Judging from the last render, the scene might benefit from a shadow setting of less that 100% in order to brighten up the areas in shadow.